37signals (formerly Basecamp before reverting to its original name) is an American web software company based in Chicago, Illinois.

[2] The open source web application framework Ruby on Rails was initially created for internal use at 37signals, before being publicly released in 2004.

The Ruby on Rails web application framework was extracted from the work on Basecamp and released as open source.

[10][11] The same year, Jason Fried, 37signals CEO, was included among MIT Technology Review's TR35 honoring technologists and scientists under the age of 35 for their ground-breaking inventions and research.

[17][18] Basecamp responded by announcing several policy changes, such as forbidding "societal and political discussions" in internal forums, which Fried described as a "major distraction.

Its primary features are to-do lists, milestone management, forum-like messaging, file sharing, and time tracking.

[26] In 2024 37signals re-launched Campfire as part of their ONCE line of products, allowing customers to buy the software outright to self-host on their own servers.

[30] Ruby on Rails is a free web application framework created by David Heinemeier Hansson, now a partner at Basecamp.